Electronics And Communication - ECE 2016 GATE Paper (Practice Test) - Electronics and Communication Engineering (ECE) MCQ

In a huge pile of apples and oranges, both ripe and unripe mixed together, 15% are unripe fruits,
Of the unripe fruits, 45% are apples, Of the ripe ones, 66% are oranges. If the pile contains a total
of 5692000 fruits, how many of them are apples?

Michael lives 10 km way from where I live. Ahmed lives 5km away and Susan lives 7 km away from where I live. Arun is farther away than Ahmed but closer than Susan from where I live. From the information provided here, what is one possible distance (in km) at which I live from Arun’s place?

Q.6 – Q.10 Carry two marks each

Q.

A person moving through a tuberculosis prone zone has a 50% probability of becoming infected.
However, only 30% of infected people develop the disease. What percentage of people moving
through a tuberculosis prone zone remains infected but does not shows symptoms of disease?

In a world filled with uncertainty, he was glad to have many good friends. He had always assisted
them in times of need and was confident that they would reciprocate. However, the events of the
last week proved him wrong.
Which of the following interference(s) is/are logically valid and can be inferred from the above
passage?
(i) His friends were always asking him to help them
(ii) He felt that when in need of help, his friends would let him down.
(iii) He was sure that his friends would help him when in need.
(iv) His friends did not help him last week.

Leela is older than her cousin Pavithra, pavithra’s brother Shiva is older than Leela. When Pavithra
and shiva are visiting Leela, all three like to play chess. Pavithra wins more often than Leela does.
Which one of the following statements must be TRUE based on the above?

P,Q,R and S are working on a project. Q can finish the taks in 25 days, working alone for 12 hours a day. R can finish the task in 50 days, working alone for 12 hours per day. Q worked 12 hours a day but took sick leave in the beginning for two days. R worked 18 hours a day on all days. What is the ratio of work done by Q and R after 7 days from the start of the project?

Q.11 – Q.35 Carry one mark each.

Q. Let M4 = I (where I denotes the identity matrix)and M ? I, M2 ? I and M3 ? I. Then, for any
natural number k, M–1 equals:

The second moment of a Poisson-distributed random variables is 2. The mean of the random variable is _____.

Given the following statements about a function f: R→R, select the right option:
P : If f(x) is continuous at x = x0, then it is also differentiable at x = x₀
Q : If f(x) is continuous at x = x0, then it may not be differentiable at x = x₀
R : If f(x) is continuous at x = x0, then it is also different at x = x₀

Which one of the following is a property of the solutions to the Laplace equation : 

Consider the plot of f(x) versus x as shown below

Suppose which one of the following is a graph of F(x)?

Which one of the following is an eigen function of the class of all continuous-time, linear, timeinvariant
systems (u(t) denotes the unit-step function) ?

A continuous –time function x(t) is periodic with period T. The function is sampled uniformly with
a sampling period Ts. In which one of the following cases is the sampled signal periodic ?

Consider the sequence x[n] = aⁿ u[n] +bⁿ u[n], where u[n] denotes the until-step sequence and 0 <
|a| < |b| <1. The region of convergence (ROC) of the z-transform of x[n] is

Consider a two-port network with the transmission matrix :   If the network is
reciprocal, then

A continuous-time sinusoid of frequency 33 Hz is multiplie with a periodic Dirac impulse train of
frequency 46 Hz. The resulting signal is passed through an ideal analog low-pass filter with a
cutoff frequency of 23Hz. The functional frequency (in Hz) of the output is _____.

A small percentage of impurity is added to intrinsic semiconductor at 300 K. Which one of the
following statements is true for the energy band diagram shown in the following figure?

Consider the following statements for a metal oxide semiconductor field after effect transistor
(MOSFET):
P : As channel length reduces, OFF-state current increases
Q : As channel length reduces, output resistance increases
R : As channel length reduces, threshold voltage remains constant
S: As channel reduces, ON current increases.
Which of the above statements are INCORRECT?

Consider the constant current source shown in the figure below. Let ? represent the current gain of
the transistor

The load current I0 through R_L is

The following signal Vi of peak voltage 8V is applied to the non-inverting terminal of an ideal
Opamp. The transistor has V_BE = 0.7 V, β = 100; V_LED = 1.5V, V_CC = 10V and –V_CC = – 10V.

The number of times the LED glows is –––––

Consider the oscillator circuit shown in the figure. The function of the network (shown in dotted
lines) consisting of the 100 k? resistor in series with the two diodes connected back-to-back is to:

The block diagram of a frequency synthesizer consisting of Phase Locked Loop (PLL) and a
divide-by-N counter (comprising /2, /4, /8, /16 outputs) is sketched below. The synthesizer is
excited with a 5 kHz signal (Input 1). The free-running frequency of the PLL is set to 20kHz.
Assume that the commutator switch makes contacts repeatedly in the order 1-2-3-4.

The corresponding frequencies synthesized are:

The output of the combinational circuit given below is

What is the voltage V_out in the following circuit?

Match the inferences X, Y, and Z, about a system, to the corresponding properties of the elements
of first column in Routh’s Table of the system characteristic equation.
X: The system is stable …..                   P: … When all elements are positive
Y: The system is unstable …                Q: … When any on element is zero
Z: The test breaks down ….                  R: … When there is a change in sign of coefficients

A closed-loop control system is stable if the Nyquist plot of the corresponding open-loop transfer
function